In the highlighted paper, Demétrio de Souza et al. showed rather elegantly, that, after gargling with a solution of PARP-FL, tumour tissue could be identified and removed in a series of oral cancer patients, despite its fluorescence in the green part of the light spectrum, generally seen as sub-optimal for optical imaging (Demetrio de Souza Franca et al. 2021). This evidence concerns the gene PARP1 and lip and oral cavity carcinoma.